Connie has 13 marbles. Juan has 5 marbles. How many more marbles does Connie have than Juan?
Direct Modeling - students will match items in a one-to-one correspondence between sets until one set is exhausted. This shows the difference the student is looking for (see example on page 17).
Connie
Juan
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Modeling -students will match items in a one-to-one correspondence between sets until one is exhausted again, but will not follow the exact order of the numbers appearing in the problem.
5+ unknown amount = 13
5 +1 +1 +1 +1 +1 +1 +1 +1=13
Counting (Children's Mathematics Cognitive Guided Instruction pg.18) Students begin with the known and count down or up in order to arrive at the unknown number.
13-5= ? 13 count back to 5 (13, 12, 11, 10, 9, 8, 7, 6, 5) to find the unknown difference of 8
5+?= 13 5 count up to 13 (5, 6, 7, 8, 9, 10, 11, 12, 13) to find the unknown difference of 8
Number Facts (Children's Mathematics Cognitive Guided Instruction pg.24)
Students work to build a group of "friendly numbers" that help them solve for the "unknown". In this case, the student starts with a total of 13, subtracts 3 (of the 5) to get to 10, and then subtracts the final 2 (of the 5). This leaves them with 8 - the unknown. (ex: 13-3 >10-2=8)
Connie has 13 marbles. Juan has 5 marbles. How many more marbles does Connie have than Juan?
Direct Modeling - students will match items in a one-to-one correspondence between sets until one set is exhausted. This shows the difference the student is looking for (see example on page 17).
Modeling -students will match items in a one-to-one correspondence between sets until one is exhausted again, but will not follow the exact order of the numbers appearing in the problem.
5+ unknown amount = 13
5 +1 +1 +1 +1 +1 +1 +1 +1=13
Counting (Children's Mathematics Cognitive Guided Instruction pg.18) Students begin with the known and count down or up in order to arrive at the unknown number.
13-5= ?
13 count back to 5 (13, 12, 11, 10, 9, 8, 7, 6, 5) to find the unknown difference of 8
5+?= 13
5 count up to 13 (5, 6, 7, 8, 9, 10, 11, 12, 13) to find the unknown difference of 8
Number Facts
(Children's Mathematics Cognitive Guided Instruction pg.24)
Students work to build a group of "friendly numbers" that help them solve for the "unknown". In this case, the student starts with a total of 13, subtracts 3 (of the 5) to get to 10, and then subtracts the final 2 (of the 5). This leaves them with 8 - the unknown. (ex: 13-3 >10-2=8)